This invention relates to a casting apparatus for use in filling internal cavities in a material or body with molten material which is allowed to solidify, and more particularly, to an improved centrifugal casting apparatus.
Centrifugal casting apparatus are employed to fill cavities within a body with, for example, molten metal such as lead, or with impregnating material such as a synthetic resin, or the like. Such cavities can be open pores in, for example layers, such as electrode layers of porous material. Cavities to be considered herein can also be cavities existing in bodies, for instance in the nature of caverns such as, for example, in the manufacture of multi-layer ceramic capacitors (see U.S. Pat. Nos. 3,679,950; 3,965,552; and 4,030,004) or such as generated in multi-layer wirings in ceramic substrate plates in the respective manufacturing steps. The pores and the cavities present in the bodies are of the open cell-type (i.e., open toward the outside) namely in order to permit filling with the molten material in, preferably, an evacuated environment.
Linn Elektronik, D 8549 Hirschbach, [Federal Republic of Germany] (see brochure number 02/85-2/2000 Schleuderarm Vacuumausfuhurung) manufactures apparatus with which test specimens can be manufactured by spin casting. The apparatus comprises a crucible for melting metal contained therein (of which the specimens are to be cast) and the casting mold. The melting crucible is radially spaced from the centrifugal axis in the centrifugal device so that upon rotation, molten material contained in the crucible rises along a sloped or obliquely directed wall and, when a sufficient centrifugal force has been reached, the molten material reaches an outlet opening in the melting crucible. The molten material flows out of the crucible through this outlet opening into a casting mold spaced radially further from the centrifugal axis. The molten material introduced into this casting mold under centrifugal pressure remains therein until it has solidified. As is standard in spin casting, a relatively dense cast structure is produced.
Using features of the principle of spin casting, the object of the present invention is to provide an apparatus for filling cavities in material or in bodies, whereby an optimum degree of filling of such cavities is achieved with the assistance of specific developments of these measures.
These and other objects of this invention will become apparent from the following description and appended claims.